| /* |
| * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /*SAM types: |
| 1. An interface that has a single abstract method |
| 2. Having more than one distinct methods, but only one is "real", the others are overriden public methods in Object - example: Comparator<T> |
| 3. Having more than one methods due to inheritance, but they have the same signature |
| 4. Having more than one methods due to inheritance, but one of them has a subsignature of all other methods |
| a) parameter types compatible |
| b) return type substitutable |
| c) thrown type not conflicting with the thrown clause of any other method |
| d) mixed up |
| 5. Type-dependent SAM types |
| non-SAM types: |
| 6. An interface that has a single abstract method, which is also public method in Object |
| 7. Having more than one methods due to inheritance, and none of them has a subsignature of all other methods |
| */ |
| |
| import java.util.List; |
| import java.util.Collection; |
| import java.sql.SQLException; |
| import java.sql.SQLTransientException; |
| import java.util.concurrent.TimeoutException; |
| import java.io.*; |
| |
| interface A {int getOldest(List<Number> list);} |
| interface B {int getOldest(List list);} |
| interface C {int getOldest(List<?> list);} |
| interface D {int getOldest(List<Integer> list);} |
| interface E {int getOldest(Collection<?> collection);} |
| //Not SAM type, case #7 |
| interface DE extends D, E {} |
| |
| interface Foo {int getAge(Number n);} |
| interface Bar {int getAge(Integer i);} |
| //Not SAM type, case #7 |
| interface FooBar extends Foo, Bar {} |
| |
| //Not SAM type, case #6 |
| interface Planet {boolean equals(Object o);} |
| |
| // SAM type interfaces: |
| // type #2: |
| //only one abstract non-Ojbect method getAge() |
| interface Mars<T> extends Planet {int getAge(T t);} |
| //only one abstract non-Ojbect method increment() |
| interface Jupiter { |
| boolean equals(Object o); |
| String toString(); |
| int increment(int i); |
| } |
| |
| // type #3: |
| interface X {int getTotal(List<String> arg);} |
| interface Y {int getTotal(List<String> strs);} |
| //SAM type ([List<String>], int, {}) |
| interface XY extends X, Y {} |
| //SAM type ([List<String>], int, {}) |
| interface XYZ extends X, Y, XY {} |
| |
| // type #4 a): |
| //SAM type ([List], int, {}) |
| interface AB extends A, B {} |
| |
| // type #4 b): |
| interface F {Number getValue(String str);} |
| interface G {Integer getValue(String str);} |
| interface H {Serializable getValue(String str);} |
| interface I {Object getValue(String str);} |
| //SAM type ([String], Integer, {}) |
| interface FGHI extends F, G, H, I {} |
| |
| interface J {List<Number> getAll(String str);} |
| interface K {List<?> getAll(String str);} |
| interface L {List getAll(String str);} |
| interface M {Collection getAll(String str);} |
| //SAM type ([String], List<Number>/List, {}) - the return type is flexible to some degree |
| interface JK extends J, K {} |
| //SAM type ([String], List<Number>/List, {}) |
| interface JL extends J, L {} |
| //SAM type ([String], List<Number>/List, {}) |
| interface JKL extends J, K, L {} |
| //SAM type ([String], List<Number>/List, {}) |
| interface JKLM extends J, K, L, M {} |
| |
| // type #4 c): |
| interface N {String getText(File f) throws IOException;} |
| interface O {String getText(File f) throws FileNotFoundException;} |
| interface P {String getText(File f) throws NullPointerException;} |
| //SAM type ([File], String, {FileNotFoundException}) |
| interface NO extends N, O {} |
| //SAM type ([File], String, {}) |
| interface NOP extends N, O, P {} |
| |
| interface Boo {int getAge(String s) throws IOException;} |
| interface Doo {int getAge(String s) throws SQLException;} |
| //SAM type ([String], int, {}) |
| interface BooDoo extends Boo, Doo {} |
| |
| // type #4 d): |
| interface Q {Iterable m(Iterable<String> arg);} |
| interface R {Iterable<String> m(Iterable arg);} |
| //SAM type ([Iterable], Iterable<String>/Iterable, {}) |
| interface QR extends Q, R {} |
| |
| interface U {Collection foo(List<String> arg) throws IOException, SQLTransientException;} |
| interface V {List<?> foo(List<String> arg) throws EOFException, SQLException, TimeoutException;} |
| interface W {List<String> foo(List arg) throws Exception;} |
| //SAM type ([List<String>], List<String>/List, {EOFException, SQLTransientException}) |
| interface UV extends U, V {} |
| // SAM type ([List], List<String>/List, {EOFException, SQLTransientException}) |
| interface UVW extends U, V, W {} |
| |
| // type #5: |
| // Not a SAM because sam-ness depends on instantiation of type-variables |
| interface Qoo<T> {void m(T arg);} |
| interface Roo<S extends Number> {void m(S arg);} |
| interface QooRoo<T1, T2 extends Number, T3> extends Qoo<T1>, Roo<T2> {} |